1. Field of the Invention
The invention lies in the field of collecting and processing multi-part folded printed products and relates to a device and a method for the collection, transport, possible processing and the stitching of printed products.
2. Discussion of Related Art
Collecting and stitching devices with endlessly revolving conveyor members, which comprise a plurality of rests, are known from the state of the art. Basically, collecting and stitching devices serve for the manufacture of magazines, newspapers, brochures etc., from finished printed and folded sheets. For this, the printed sheets and the cover are applied over one another, aligned and stitched, in the desired sequence.
A device for processing folded printed sheets is known from EP0202507, with which a plurality of saddle-like rests are provided for the straddled receipt of the printed sheets along a conveyor path, with a rest edge aligned transversely to the conveyor path. The endlessly revolving conveyor member transports the saddle-like rests past a plurality of working stations, wherein at least one working station is a stitching station with revolving stitching heads. A product to be stitched is lifted from the saddle from below, in each case by a separately driven anvil and is stitched from above by way of a stitching head which synchronously runs with it. The anvil and stitching head, when stitching, are in each case located in a perpendicular position in relation to the plane, through which the rest edges run along the conveyor path. The anvil is mounted in a vertically upwardly movable manner on its conveyor belt, in the region of the cooperation, whilst the stitching head is arranged in a fixed position in this spatial direction. With this orthogonal guidance of the stitching head and saddle, the time which is available for stitching is set in a fixed manner on account of the length of the region of cooperation and the speed of the conveyor means. If the conveyor speed is to be increased, then the time which is available for stitching necessarily, is compellingly shortened. Moreover, the lifting of the printed sheets from the saddle, which is envisaged there, is laborious and is disadvantageous with regard to the precision on the stitching.
A further gathering and stitching device is described in DE19638448, with which again saddle-like rests are transported along a conveyor path with rest edges directed transversely to the conveyor path, past at least one working station. The saddle-like rests are movably mounted on their pull member, so that their rest edges may run through a movement path which is in opposite directions to the transport movement, with the passage through the region of the cooperation with the stationary working station, so that approximately a temporary standstill of the rest edges relative to the fixedly arranged working station, in particular a product feed station, is achieved. Again for stitching, it is suggested to reduce the relative speed of the saddle-like rests in relation to the stationary stitching apparatus. This is effected by way of two crank drives which are arranged in a manner which is fixed with regard to movement, are driven equal in phase and which slow down the components of the speed of the rests, which are directed parallel to the conveyor path, on transport past the stationary stitching apparatus in a first phase, then briefly keep them close to the value zero and subsequently accelerate them back to the speed of the pull member. The saddle-like rests thereby always remain aligned orthogonally to the conveyor path. With the conveyor speeds which are common today in the medium performance or high performance field, such a speed reduction and subsequent acceleration entails enormous loading of the participating components. The time of cooperation of the stitching head and the saddle-like rest is again compellingly set by the speed of the conveyor means. Moreover, the change of the relative speed of the rest to the working station may be influenced purely by the control of the rest.
A collecting and stitching device is known form EP566531, with which the rests after the end of the feed, are led to a deflection wheel comprising a bending device. It is described that the rests in the deflection wheel come to lie on bending devices aligned in the stitching movement direction. The bending devices and rests must be guide over one another in a precise manner, in order to ensure a stable stitching position. Particularly high demands are made with regard to the meshing of the rests into the stitching drum. Since the feed of the printed products to the deflection wheel takes up much space, it is suggested to design the rests in a pivotable manner about an axis between the conveyor chains of the pull means, said axis running transversely to the conveyor direction, so that they may be rotated in the run-in section. A control cam is provided for this, by way of which the rests may be pivoted in a positive manner. After meshing into the deflection wheel, the rests are held in their defined radial position and rotate about the axis of the deflection wheel. It is disclosed that the stitching device comprises several rotation stitching heads which are driven synchronously with the deflection wheel on a parallel circular arc with the stitching procedure. A pivoting of the rests between the conveyor chains of the pull means in the stitching region is no longer possible.
A device for wire stitching multi-part printed products on a collection drum by way of a rotating stitching unit with a plurality of circularly revolving stitching heads is known from EP546326. The likewise circularly revolving rests of the collection drum, in a region of the cooperation, force the stitching heads against the inside of their circular revolving path, so that a flattening of this circular path is effected in the stitching region. The result of this is that the stitching heads may accompany the rests for a certain while. An extension of the stitching region is achieved by way of this. This contributes to the staples being driven into the printed products in a perfect manner at the correct location and in the correct position and being able to be well bent. Preferably, the stitching heads during the stitching procedure are held in an exactly aligned or approximately aligned position with an associated rest, by which means the conditions under which the staples are inserted, are once again improved. The maintenance of the aligned position must be accomplished solely by the pivot movement of the stitching heads, since the rests in the drum are not pivotably movable.
It is then the object of the present invention to provide a device and a method of the initially cited type, with which the disadvantages cited above are largely overcome, and with which the time which is available for an optimal stitching result, is no longer compellingly dependent on the conveyor speed of the conveyor member. This is to be rendered possible without having to compromise with regard to the quality of the stitching result. A perfect and positionally correct stitching of printed products is to be made simple, even at greater working speeds.
A further object of the invention lies in permitting a change in the course of the processing with relatively little effort.
According to the invention, this object is achieved by a device with the features of the characterizing part of claim 1 and by a method with the features of patent claim 13.